So dark the con of man

So dark the con of man is the message Jacques Saunière scrawled across the protective glass of the Mona Lisa in his own blood, using a black-light stylus. It is the final clue in the elaborate code he left for his granddaughter, Sophie Neveu, and it encapsulates the Priory of Sion's core belief: that the early Christian Church deliberately suppressed the sacred feminine, demonized goddess worship, and rewrote history to consolidate patriarchal power.

Origin and Discovery

The message was written with a watermark stylus, invisible to the naked eye, and was revealed only when Sophie Neveu shone a portable ultraviolet light on the painting. The six words, "So dark the con of man," appeared glowing in purple across the face of Leonardo da Vinci's most famous work. This discovery came after Sophie and Robert Langdon had already deciphered the anagram "O, Draconian devil! Oh, lame saint!" to reveal "Leonardo da Vinci! The Mona Lisa!" The message was the culmination of a chain of clues left by Saunière, who had arranged his own body in the pose of Da Vinci's Vitruvian Man and drawn a pentacle on his abdomen. The phrase itself is a direct accusation, a final, defiant statement from a dying man.

Meaning and Thematic Significance

The phrase "So dark the con of man" is a proclamation of the Priory of Sion's most fundamental philosophy. It refers to the historical campaign by the early Roman Catholic Church to eradicate pagan religions and convert the masses to Christianity. Langdon explains to Sophie that the Church launched a smear campaign against pagan gods and goddesses, recasting their divine symbols as evil. The pentacle, a pre-Christian symbol of the sacred feminine and the goddess Venus, was distorted into a sign of the devil. The message is a lament for the obliteration of the sacred feminine from modern religion, a process Langdon describes as the Church's brutal crusade to "reeducate" pagan and feminine-worshipping religions over three centuries. The phrase directly references the Church's propaganda and bloodshed, which Langdon argues successfully banished women from the temples of the world and recast the once-hallowed act of Hieros Gamos as shameful.

Connection to the Priory's Mission

The message is not merely a historical observation but a direct expression of the Priory of Sion's purpose. The Priory's tradition of perpetuating goddess worship is based on the belief that powerful men in the early Christian church "conned" the world by propagating lies that devalued the female. The Priory believes that Constantine and his male successors converted the world from matriarchal paganism to patriarchal Christianity through a campaign of propaganda that demonized the sacred feminine. The message "So dark the con of man" is a rallying cry against this historical deception. It is also a clue that leads Sophie to the second Da Vinci painting, Madonna of the Rocks, where she finds the gold key to a Swiss bank deposit box, which in turn contains the keystone. The message thus serves as both a philosophical statement and a practical step in the treasure hunt.

Role in the Narrative

For Sophie, the message is a direct communication from her grandfather, confirming that he was a member of the Priory and that his final actions were a deliberate attempt to pass on a secret. It reinforces the central conflict of the novel: the struggle between the truth of the sacred feminine, as guarded by the Priory, and the institutional power of the Church, which has worked to suppress it. The phrase "So dark the con of man" is a key piece of evidence that helps Sophie and Langdon understand the stakes of their quest. It is a stark, bitter summary of the historical injustice that the novel's plot seeks to expose and, in its own way, redress.